[zorg] r314540 - [llvmlab] Add timeout and retries for fetching builds.

[Volodymyr Sapsai via llvm-commits]

Author: vsapsai
Date: Fri Sep 29 10:24:48 2017
New Revision: 314540

URL: http://llvm.org/viewvc/llvm-project?rev=314540&view=rev
Log:
[llvmlab] Add timeout and retries for fetching builds.

In case of network problems, time out after 5 seconds instead of relying on OS
to close the connection which can take more than 20 minutes. Timeout value is
measured between successfully transmitted packets, not for entire transaction.
So we don't require big files to be downloaded in 5 seconds but we require not
to get stuck for more than 5 seconds.

Reviewers: cmatthews, JDevlieghere

Reviewed By: cmatthews

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D38281


Modified:
    zorg/trunk/llvmbisect/llvmlab/gcs.py

Modified: zorg/trunk/llvmbisect/llvmlab/gcs.py
URL: http://llvm.org/viewvc/llvm-project/zorg/trunk/llvmbisect/llvmlab/gcs.py?rev=314540&r1=314539&r2=314540&view=diff
==============================================================================
--- zorg/trunk/llvmbisect/llvmlab/gcs.py (original)
+++ zorg/trunk/llvmbisect/llvmlab/gcs.py Fri Sep 29 10:24:48 2017
@@ -3,6 +3,7 @@
 """
 import os
 import requests
+import urllib3
 
 # Root URL to use for our queries.
 GCS = "https://www.googleapis.com/storage/v1/"
@@ -11,6 +12,21 @@ DEFAULT_BUCKET = "llvm-build-artifacts"
 
 BUCKET = os.getenv("BUCKET", DEFAULT_BUCKET)
 
+class HttpClient(object):
+    def __init__(self):
+        self.session = requests.Session()
+        # Retry after 0s, 0.2s, 0.4s.
+        retry = urllib3.util.retry.Retry(total=3, backoff_factor=0.1)
+        adapter = requests.adapters.HTTPAdapter(max_retries=retry)
+        self.session.mount('https://', adapter)
+
+    def get(self, url, **kwargs):
+        if "timeout" not in kwargs:
+            kwargs["timeout"] = 5  # seconds
+        return self.session.get(url, **kwargs)
+
+HTTP_CLIENT = HttpClient()
+
 
 def fetch_builders():
     """Each build kind is stored as a folder in the GCS bucket.
@@ -18,7 +34,7 @@ def fetch_builders():
     compilers.
     """
     params = {'delimiter': "/", 'fields': "prefixes,nextPageToken"}
-    r = requests.get(GCS + "b/" + BUCKET + "/o", params=params)
+    r = HTTP_CLIENT.get(GCS + "b/" + BUCKET + "/o", params=params)
     r.raise_for_status()
     reply_data = r.json()
     assert "nextPageToken" not in reply_data.keys(), "Too many builders!"
@@ -36,13 +52,13 @@ def fetch_builds(project):
     params = {'delimiter': "/",
              "fields": "nextPageToken,kind,items(name, mediaLink)",
              'prefix': project + "/"}
-    r = requests.get(GCS + "b/" + BUCKET + "/o", params=params)
+    r = HTTP_CLIENT.get(GCS + "b/" + BUCKET + "/o", params=params)
     r.raise_for_status()
     reply_data = r.json()
     all_data['items'].extend(reply_data['items'])
     while reply_data.get('nextPageToken'):
         params['pageToken'] = reply_data['nextPageToken']
-        r = requests.get(GCS + "b/" + BUCKET + "/o", params=params)
+        r = HTTP_CLIENT.get(GCS + "b/" + BUCKET + "/o", params=params)
         r.raise_for_status()
         reply_data = r.json()
         all_data['items'].extend(reply_data['items'])
@@ -54,7 +70,7 @@ CHUNK_SIZE = 5124288
 
 def get_compiler(url, filename):
     """Get the compiler at the url, and save to filename."""
-    r = requests.get(url)
+    r = HTTP_CLIENT.get(url)
     r.raise_for_status()
     with open(filename, 'wb') as fd:
         for chunk in r.iter_content(CHUNK_SIZE):